We examined the expression of epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), epidermal growth factor receptor (EGFR) and p185c-erbB-2 immunohistochemically and correlated the expression with growth in 66 cases of human gastric carcinoma. To evaluate growth, we used the bromodeoxyuridine (BrdU) labeling index in 51 cases and the radiographic growth rate in 15 cases. Expression of EGF was detected in 41 cases (62.1%), TGF-alpha in 42 cases (63.6%), EGFR in 34 cases (51.5%), and p185c-erbB-2 in 37 cases (56.1%). The BrdU labeling index ranged from 1.5 to 32.0%. The BrdU labeling index was higher in tumors that coexpressed EGF and EGFR or TGF-alpha and EGFR than in tumors without expression or in tumors that expressed growth factors or the receptors (p < 0.01). The BrdU labeling index was also significantly higher in tumors with the expression of EGFR and/or p185c-erbB-2. Tumors with simultaneous expression of EGF, TGF-alpha, EGFR and p185c-erbB-2 had an association with a high BrdU labeling index. Moreover, all of these growth factors and receptors were expressed simultaneously in gastric carcinomas with rapid growth. These results suggest that the expressions of EGF, TGF-alpha, EGFR and p185c-erbB-2 are closely related and then play an important role in the growth of human gastric carcinomas.